Papers by Keyword: Encapsulation

Abstract: In this work, encapsulation technology—nanoemulsions (NEs) and nanostructured lipid carriers (NLCs)—was applied for color masking of betel nut extract for oral and skin applications. Types and extents of surfactant and lipid as well as homogenization process showed essential roles on physical properties of the encapsulated betel nut extract. Comparing to solution of betel nut extract in methanol, the degree of lightness of the optimized NE and NLC formulations improved more than 44 time compared to unencapsulated formulation. The optimized NE and NLC were most stable at 25 °C. Extreme storage conditions of 4 and 45 °C resulted in phase separation and color change, respectively. However, total phenolic and antioxidant activity were found stable during the stability test in all storage conditions. This work has shown a great potential use of nanoencapsulation technology in color masking plus maintain activities of betel nut extract for food as well as cosmetic application.

Abstract: The purpose of this study was to investigate the influence of process parameters on the characteristics of microparticles using double emulsion solvent evaporation method for encapsulation of hydrophilic drug. Donepezil hydrochloride (DPH), a reversible cholinesterase inhibitor, was selected as a model hydrophilic drug. Prior to conducting an experiment, the target particle size of microparticles was set at approximately 200 μm. The investigated process parameters include pH of outer water phase, stirring time, polymer amount, and volume of outer water phase. The results showed that DPH-loaded microparticles was successfully prepared in two steps. In the first step, the primary emulsion was prepared by dissolving DPH in distilled water before emulsifying in dichloromethane (DCM) containing different amounts of poly(butylmethacrylate-co-2-dimethylaminoethyl-methacrylate-co-methyl-methacrylate) (PBM-DM-MM) using ultrasonic probe. In the second step, the primary emulsion was emulsified in polyvinyl alcohol (PVA) solution by overhead stirrer to prepare double emulsion. After solvent evaporation, the microparticles were collected by centrifugation and washed with distilled water. Based on the statistical analysis, stirring time, polymer amount and volume of outer water phase were the main significant parameters influencing particle size of microparticles.

Abstract: Although caffeine was suggested as one of the pharmacological agents for the cellulite treatment, its skin permeation restricted. The present work was aimed at formulating caffeine loaded nanostructured lipid carriers (CAF-NLCs) containing coconut oil as a topical delivery system. CAF-NLCs were prepared by the ultrasonic emulsification method, using coconut oil as a liquid lipid. The proper selection of solid lipid and surfactants for these formulations were investigated. Subsequently, physicochemical properties, entrapment efficacy, stability, and in vitro drug release were evaluated. The CAF-NLCs containing coconut oil was successfully prepared using glyceryl behenate as a solid lipid and showed an interesting entrapment efficiency (62-99%). The obtained CAF-NLCs presented the nanosized range (≈ 60-390 nm), with a low polydispersity index and high negative zeta potential values (over ‐30 mV). However, the type and concentration of surfactant also affected these properties. These results suggested that CAF-NLCs containing coconut oil are the promising carrier for delivery of caffeine following topical application.

Abstract: Special Region of Yogyakarta is one of the regions that has high potential for natural disasters. Food is the most consumable material which is needed when natural disasters occur. An alternative form of food preservative is needed to maintain nutritious foods that will be distributed to the victims of natural disasters. The foods must still appropriate to eat. In this research, watermelon rind was chosen as an ingredient to make natural preservatives because they contain flavonoids and anthocyanins. This research aims were to determine the total content of anthocyanins, flavonoids and phenolics in the red watermelon rind and yellow watermelon rind, also to determine the effect of chitosan composition to the ability of flavonoids and phenolics release in the food. This research was carried out by extraction and encapsulation methods. The analysis included the content of Total Anthocyanin (TA), Total Flavonoids (TF) and Total Phenolic (TPC) in the supernatant. The other analysis was in vitro tests that was done to know the ability of flavonoids and phenolics release in the food. The total anthocyanin content in the red watermelon rind was 0.0334 mg L^-1 while in the yellow watermelon rind was 0.0668 mg L^-1. The total content of flavonoids in the red watermelon rind was 0.7369 g mL^-1, while in the yellow watermelon rind was 0.3296 g mL^-1. The total phenolic content of red watermelon rind was 0.3669 g mL^-1, while in the yellow watermelon rind was 0.2273 g mL^-1. In both of red and yellow watermelon rind, the highest release of flavonoid and phenolic levels showed in the variations of chitosan mass 0.4 grams. The highest flavonoid content released was 0.0638 g mL^-1 in red watermelon rind and 0.0702 g mL^-1 in yellow watermelon rind. The highest phenolic content released was 0.0321 g mL^-1 in red watermelon rind and 0.0408 g mL^-1 in yellow watermelon rind.

Abstract: In this study, binary Ag-alloy wires were doped with different Pd concentrations, and each wire was encapsulated in an LED package. The initial optical characteristics were tested, and reliability was tested with the high temperature storage life (HTSL), high temperature operating life (HTOL) and wet high temperature operating life (WHTOL). The luminous efficiency of the Ag-alloy wire LED package was about 2% higher than that of the Au wire package, but the addition of 6% Pd to the Ag-alloy wire decreased the luminous efficiency to close to that of the Au-wire LED package. This was due to the high reflectivity of silver in the blue wavelength region, as compared to the low reflectivity of palladium. After 1,000 hours of HTOL and WHTOL, the results showed that the performance of luminous flux maintenance increased with increasing Pd content, indicating that Ag-alloy wires doped with a sufficient amount of Pd can inhibit degradation due to oxidation reaction and thermal and humidity aging. Therefore, binary Ag-Pd alloy wires produced with specific drawing and annealing processes are suitable for mid-power white light LEDs in lighting applications.

Abstract: Apatite nuclei were obtained by raising pH of an acellular simulated body fluid (SBF). The apatite nuclei and levothyroxine particles were dispersed in an ultrapure water and the apatite nuclei were attached to the surface of the levothyroxine particles. By soaking in SBF, apatite formation was induced by the apatite nuclei located on the surface of the levothyroxine particles and the levothyroxine particles were encapsulated with apatite. We evaluated release behavior of levothyroxine in phosphate buffered saline.

Abstract: The phase change energy storage aggregate was prepared with the eutectic mixture of capric acid (CA) and stearic acid (SA) as phase change energy storage material (PCM) and waste autoclaved aerated concrete as skeleton. The results showed that the appropriate mass ratio of CA to SA is 9:1, with melting temperature 26.8°Cand latent heat of 96.4 J/g. The optimal load of PCM on waste autoclaved aerated concrete was 55%. In order to reduce leakage and increase strength of the aggregate, slag-water glass-gypsum binder was used for encapsulation, which also helped increase the compatibility with the main building materials. The simulation test showed that the phase change energy storage aggregate possesses good temperature control and energy storage performance.

Abstract: We investigated the effects of fluidized-bed coating parameters on texture and antioxidant properties of puffed pounded-unripe rice (PPUR) coated by marigold extract with variations of inlet air temperature of 50, 60 and 70°C and coating solution feed rate of 5, 7.5 and 10 ml/min. The results showed that increasing inlet air temperature tended to reduce the hardness of coated PPUR, while the adverse effect was found with increasing feed rate. Both parameters did not significantly affect the crispiness. We also found that fluidizing air temperature and feed rate significantly affect total phenolic content (TPC), total flavonoid content (TFC) and their antioxidant activities. Higher feed rate slightly increased TPC and antioxidant activities as determined by DPPH and FRAP assays, but not for TFC. As mostly found in medicinal plants, all antioxidant properties decreased when temperature increased. Based on the amount of TPC and TFC and their antioxidant activities, we recommend low inlet air temperature and high feed rate to improve health benefits of puffed pounded-unripe rice as a breakfast cereal. However, agglomeration must be concerned when using high feed rate.

Abstract: Organic/inorganic stacks were deposited on flexible polycarbonate substrate using inductively coupled plasma chemical vapor deposition (ICP-PECVD) for permeation barrier application. The effects of deposition temperature, RF power, gas flow ratio, deposition pressure on film properties of surface roughness, water vapor transmission rate (WVRT) were investigated. Energy dispersive spectrum (EDS), atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to characterize the film characteristics of the stack layers. It was found that the surface roughness Ra was as low as is 0.25 nm. The WVRT values of the optimum barriers structures were 10^-2g/m² day (1 pair of stacks) and 4.8 x 10^-5g/m² day (4 pair of stacks). This result indicated that the permeation barrier films prepared by ICP-PECVD could be a promising candidate for flexible electronic applications.

Abstract: SrAl₂O₄:Eu²⁺,Dy³⁺ phosphors were synthesized under different temperature by high temperature solid phase method. Encapsulation modification of SrAl₂O₄:Eu²⁺,Dy³⁺ by using SiO₂ glycol were made over chemically unstable against water. Photoluminescence measurement result shows that when the sintering temperature is 1300 °C, the initial afterglow brightness of SrAl₂O₄:Eu²⁺,Dy³⁺ is up to the highest, 12101 mcd/m². FTIR results showed that new IR peaks at 1085 cm⁻¹ due to the vibration of Si-O-Si and at 931cm⁻¹ due to the vibration of Si-O-Al appeared after silica encapsulation. This verified that the silica encapsulation is not only a physical absorption process but also involving chemical bonding process. Both phosphors before and after encapsulation have same emission peak at 510 nm. A dense layer of silica formed on phosphor surface has the highest water-resistance after being encapsulated for 2h under the condition of pH 4 and encapsulation amount 10:1. The pH value of aqueous solution contained phosphor was steadily 8, and the initial afterglow brightness decreased only by 9%, that is, from 12101 to 11011 mcd/m².